Which of the following formulas define norms on R3?
(a) ||v|| = √2v21 + v22 + 3v23
(b) ||v|| = √v21 + 2v1v2 + v22 + v23
(c) ||v|| = max {v1,|, |v2|, |v3|}
(d) ||v|| = {v1, - v2| + |v2 - v3| + |v3 - v1}
(e) ||v|| = |v1 - v2| + { |v1|, |v2|}